Fitbit Alta HR v Fitbit Alta

Fitbit has released another tracker to its lineup, the Fitbit Alta HR, which means the already tough decision of choosing which Fitbit is best for you just got even trickier. It doesn't help when you're looking for a stylish fitness tracker either, since there are now two vying for your wrist.

The $129 Fitbit Alta and its big brother, the $149 Alta HR, only have a few key differences. The question is: can you save a few bucks and opt for the one with a couple fewer features? Or are they features you'll definitely need, negating the price difference?

Here's our breakdown of how the two Fitbits compare in terms of features, activity and sleep tracking, battery life and more.

Fitbit Alta HR v Fitbit Alta: Design

To the untrained eye the Alta and Alta AR look almost identical, but once you take a closer look at the two you start to see how different they really are.

Firstly, and most noticeably, the Alta HR has a new band. The strap now has a buckle at the end, rather than a simple button, meaning it fastens to the wrist more securely, like the Fitbit Charge 2. It's built to be more snug on your arm so the Alta HR's heart rate sensor can work at its most accurate. It's the same for sleep tracking – it needs to be as secure as possible while also being comfortable.

Internally, Fitbit has shrunk down the chip to make room for the new sensor and a larger battery. This keeps the outside of the device as close to possible as the original while fitting more into the guts. Other than that, the two look very alike, but the Alta HR wins by having the better band. That said, straps are interchangeable between both devices, so if you just want to put a more secure clasp on your Alta, you can.

Fitbit Alta HR v Fitbit Alta: Features

The major feature difference between the Alta HR and Alta is right there in the name: a heart rate sensor. The Alta HR impressively packs a sensor into a body no bigger than the original, and keeps track of your heart rate in five-second intervals throughout the day.

Now, while Fitbit has packed in a heart rate sensor, it's not exactly the best for intense workouts. Instead, it's better for light workouts and keeping track of your resting heart rate, which is really what the Alta HR is about. It's a tracker to keep on day and night, but if you're looking for more serious fitness capabilities, you won't find them here. It does have SmartTrack though, which automatically detects what kind of activity you're doing.

The Alta, on the other hand, does not track your heart rate. Instead, you'll get your steps, distance, active time and burned calories. You do get SmartTrack, but bear in mind that you're missing heart rate and GPS, so there's going to be a lot of guesstimating going on.

And while the Alta can track sleep, the Alta HR is Fitbit's debut device for Sleep Stages, which can be paired nicely with the companion app's Sleep Insights to help you not just see how you're currently sleeping, but get better at it too.

Fitbit Alta HR v Fitbit Alta: Fitness tracking

Both devices feature SmartTrack, automatically detecting what kind of workout or activity you're doing and logging it as such, but the Alta HR gets a little more detail with the heart rate sensor.

It's definitely capable of detecting a run, and at the end of it we found you'll have a reasonably decent read-out of your HR. But because this isn't meant for more serious workouts, you won't be able to see much data on the screen beyond heart rate and distance while you're in workout mode, nor will you have as much data to interrogate afterwards – it's certainly not designed for the marathon runners.

However Fitbit also uses the heart rate monitor to improve statistics in other areas, such as calorie burn calculations, and it's good at logging your resting heart rate through the day. It does however lack the VO2 Max tracking of the Charge 2 and, more curiously, the guided breathing workouts.

The Alta can't do most of these things either, though. It can track your steps and even guess your calorie burn, but that calorie burn isn't going to be as accurate without a heart rate to measure with. Step tracking on both the Alta and Alta HR tends to overcount, as we've come to expect from Fitbit devices, but it's not on a dramatic level.

Overall, it's a no-brainer that the Alta HR offers more in the fitness department due to the heart rate sensor coming on board. It's certainly not up to the likes of the Garmin Vivosmart HR+, but it's well-equipped for day-to-day wellness tracking.

Fitbit Alta HR v Fitbit Alta: Sleep Tracking

The Alta HR's heart rate sensor is put into use for sleep tracking, making it more useful in this department. The HR uses a combination of accelerometer data and variable heart rate to track when you're in light, deep or REM sleep.

For example, when you're in REM sleep your heart rate is variable but your body is still, so by combining its sensors the Alta HR can get a better idea of what level you're in. You'll be able to see all this information in the companion app, which displays a chart showing how you swing between the three modes of sleep each night. There's also the Sleep Insights feature, which uses that information to recommend ways to get better sleep. We found that initially the insights provided are rather generic, but they become more personalised the more you use the tracker.

Fitbit's new obsession with sleep doesn't stop at the Alta HR though. Sleep Stages and Insights have also been rolled out to the Fitbit Blaze, and will come to other devices with heart rate tech, including the Charge 2, in the future.

The first Alta does sleep, but it only in the barest sense. It'll track how long you've been asleep, your restlessness and wake, but that's pretty much it. In our tests we've found it finicky, not tracking as well as we'd have hoped. As it lacks the sensor, the Alta won't be getting Sleep Stages, but it will get Insights in the app.

If you're not into sleep tracking then this part of the comparison won't matter, but if you are then the Alta HR is really where you need to be.

Fitbit Alta HR v Fitbit Alta: Battery Life

Fitbit's claims on battery life for both Alta HR and Alta are slightly inverted. The company claims the Alta HR could deliver a week of battery life, which would be impressive, but in our testing we only managed six days.

On the other hand, Fitbit claims the Alta would only deliver five days of battery life, but our testing found us getting eight days – just over a week. It's likely that not having a sensor pinging your heart rate every five seconds improves battery life considerably, and it doesn't appear that any improved software optimisation has helped. It only comes down to a matter of a day or so, anyway, which is probably not enough of a difference to offset other considerations.

Fitbit Alta HR v Fitbit Alta: Price

The Fitbit Alta starts off at $129 for the regular version and jumps up to $149 if you'd like the 22k gold-plated special edition.

The Alta HR starts off at $149 for the regular version and jumps up to $179 for either the gunmetal stainless steel or 22k rose gold plated special editions.

Fitbit Alta HR v Fitbit Alta: Verdict

The difference between the Alta HR and Alta comes down to two things: a heart rate sensor and sleep tracking.

The Alta is a capable fitness tracker that can keep track of your steps and activities, but it can't track your heart rate while you're resting and doing lower-intensity workouts.

More than that though, the Alta HR's heart rate abilities allow it to track your sleep in a much more nuanced and comprehensive way than the Alta. Rather than just keeping track of how long you sleep, it'll tell you how long you spend in each sleep stage. While we wouldn't recommend either to those looking for a high-intensity device, the Alta HR also uses its fancy new heart rate monitor to get an average heart rate throughout the day, which may be something you're after.

If you're big into sleep tracking and don't require the more in-depth data for intense workouts, the Alta HR is for you. If you'd rather have a simpler tracker with slightly longer battery life, the Alta may suffice. Ultimately it may come down to cost, but we think the HR is worth the extra for what you get.